Watch Band Sizing Guide: Finding Your Perfect 20mm Fit

Choosing the right watch band is a personal choice that balances comfort, style, and practicality. In order to determine the correct size, you must first know your wrist circumference.

You can find your wrist size by wrapping a flexible tape measure around the thinnest point of your wrist. Then, you can extrapolate that number to the specific band size.

Length

A watch strap’s length is a key component in how it looks and allowing wearers to customize their look. The ideal length will be just long enough to sit flush against your wrist with no excess material. It should also be just tight enough to ensure that it stays securely in place and doesn’t fall off your wrist. A too loose fit will feel unmanageable and lack refinement, while an excessively tight fit can be uncomfortable.

For a general rule of thumb, we recommend that your strap’s length be approximately the same as your wrist circumference (minus 1”). To measure your wrist size, simply wrap a piece of string around where you would normally wear your watch and mark it where the ends meet. Then, use a ruler or a tape measure to get the length in inches and convert that number to millimeters.

If you’re using a band from an old watch, the length may already be marked on the back of the strap near the lugs where it attaches to the case. If that’s the case, you can still measure the length by running your finger between the lugs and determining where the band begins and ends (excluding the buckle).

The width of a watch strap is another important factor in how it fits on your wrist. While this may not be as crucial a dimension as the length, it can still have a big impact on how your watch looks and feels. We generally suggest that the band’s width should be roughly half of the watch case’s diameter.

Ultimately, the perfect strap width comes down to personal preference. Some people prefer a slimmer look, while others prefer a wider strap with a more substantial feel. As such, it’s best to experiment with different strap widths and find one that works well for you. If you are unsure what size to choose, we recommend trying on multiple straps in person to find the right fit. If that’s not possible, our sizing guide should help you narrow down your options. Our recommendations are based on the average widths of our various straps and should provide a good starting point for your search.

Width

The width of a watch band is less directly related to wrist size than length, but it can still be an important factor. A wide watch strap can look great on a larger wrist, while a narrow one might not be the best choice for a smaller wrist.

Watch band width is usually given in millimeters, and it refers to the distance between the lugs where the strap attaches to the watch case. You can often find this information printed on the back of your existing watch, or you can measure the distance with a metric ruler or free printable template (be sure not to include the spring bar in the measurement).

If your wrist is on the small side, consider a slightly thinner band for a balanced appearance. On the other hand, a thick watch strap can look oversized on a small wrist and may even cause discomfort.

Many watch cases also come in different diameters, which can affect how a specific watch looks on your wrist. In general, a wrist circumference of six inches or so will look best with a case that is around 38 to 46 millimeters in diameter.

Generally speaking, you will want your new watch strap to be about the same width as the case for the most comfortable fit. However, it is always better to be a little bit snug than too loose when choosing a replacement watch strap.

For the most accurate wrist sizing, break out your soft tape measure or a standard cloth measuring tape and wrap it around your wrist at the point where you like to wear a watch. Then, using a ruler or a soft tape measure, mark the length of your wrist from your crease at the base of the thumb to the end of the wrist bone. You should also take into account the thickness of your watch strap, as some bands are thicker at the buckle end than they are at the lug end.

Height

As with length, the height of a Watch Band depends on wrist circumference and personal preference. As a rule, watch bands should be no more than an inch taller than the case diameter they’re intended for. Choosing a strap that’s too small can create tension or leave noticeable marks on your wrist, while one that’s too large can throw off the overall balance of the design.

The best way to determine a suitable strap size is to measure your wrist circumference using any household item you have handy (like a piece of tape or a strip of paper) and use the measurement as your reference. However, since wrist sizes vary widely, it’s also a good idea to consult the product description or sizing chart for each band you’re considering. You may even find some have sizing recommendations that include a numbered size range instead of a general Small, Medium, or Large.

While you can use the sizing chart provided by your preferred manufacturer to get a general idea of what size watch band you need, it’s always a good idea to double-check the measurements with a ruler or caliper. This is especially true if you’re replacing an existing strap, as it’s possible that it could have shrunk due to heat or moisture.

If you’re looking to replace an existing Apple Watch band, check the back of the original strap for any stampings that indicate its width, or measure it between the lugs where it attaches to the watch with a ruler or a digital caliper. Some manufacturers include lug width specifications on their websites or in their official product documentation.

Once you’ve found a band that matches your wrist size and style, consider the thickness of the material to ensure a comfortable fit. Thicker materials such as leather tend to be more supple and flexible, while nylon or plastic ones are typically thinner and stiffer. For a comfortable, secure fit that doesn’t feel constricting or leave marks on your wrist, look for a strap with a thickness between 4 and 6 millimeters.

Thickness

When you’re shopping for a Watch Band, thickness is another important factor to consider. Thicker bands can add a more formal or dressier look, and they may also be more comfortable for some wearers. However, thickness can also impact how well a band fits on the wrist, so it’s important to measure carefully.

The best way to determine the thickness of a watch band is by measuring the width between the lugs where the strap attaches to the case. You can do this using a ruler or other flexible measurement tool, such as string or a strip of paper. Just make sure that the measuring tool is snug against your wrist, as you’ll want a tight fit to ensure that sensors can properly measure the movement of your arm.

You can also check the sizing of an existing band by looking at the back of the band for any stamping that indicates the width in millimeters. If you’re not able to find this information, you can use a flexible tape measure or a piece of string and wrap it around your wrist where you would wear a watch. Then, mark where the end of the strip overlaps and measure the marked length with a ruler to get the width in mm.

For Apple Watch bands, the thickness is often listed as a range or as a single number. This is because many Apple Watch models have different sizing, so the thickness of the band can vary depending on the model.

Some bands have specific sizing recommendations, so it’s best to refer to the product description or sizing chart for these bands. Generally, the recommended sizing is based on wrist circumference. So, for example, a wrist circumference of six inches usually looks best with a 38-millimeter case size; six-and-a-half inch looks best with a 40-millimeter case size; and seven-inch looks good with most 42-millimeter cases.

Other types of bands may have a more limited range of sizing, but they typically still fall within a similar range. For instance, the Modern Buckle is only available in a few sizes, so if your wrist is larger than that range, you’ll need to choose a different band.